EDIT: Sorry, maybe should have put this in the Processing forum!
I have been curious to know how people are using LAB in RawTherapee for making contrast/ tonal, color adjustments, and how these are combined with other adjustments outside the LAB space. I must thank Andy Astbury for his excellent video on this, which finally pushed me toward expanded use of LAB several years ago.
Do you have a particular order in which you do LAB adjustments? Do you adjust color balance outside LAB–i.e, using an eyedropper tool? (I rarely use this, but adjust A and B channels until they look right. )
To start, I always load a pre-set processing profile (incl, dual demosaicing, global chrominance noise reduction, etc) as recommended by Andy.
I often make some rough adjustments to contrast/tone in the L channel, and then sometimes go over to Local Contrast, then come back to L channel, sometimes followed by A, B, and often, CC or CH, and/or HH. I assume mixing RGB edits with LAB does not make any difference as long as there are no noticeable color shifts (?)
I have been playing around with split toning using the B channel–warm highlights and cold shadows. Do you do split toning in LAB? If so, how?
Any other LAB tricks and tips, I would be interested to hear! Thanks.
I don’t really treat LAB adjustments different from anything else. I often start with ‘auto exposure correction’ to get started, tweaking the result if it’s close, or undoing it and starting from scratch if not. The RGB lightness slider is my next stop, to get the general exposure dialed in a bit.
From there I often use LAB for contrast adjustments, and to tweak individual colors via the CH and LH equalizers. Usually I do curves in LAB too.
I do like the highlights and shadows sliders in RGB though, and will mix those in along with my LAB adjustments, particularly when the image has interest in those extremes (e.g., dappled sunlight in the woods).
For saturation I use the vibrance tool in the colour tab. For colour toning/split toning, I use either the tools on the colour tab, or in the local adjustments/selective editing tab.
Generally though, I have a rough schedule of things I do, but I will often bounce back and forth to get the right combination of effects from multiple tools. e.g., after setting LAB adjustments, moving on to colour toning, then readjusting the LAB to account for colours.
